Weegy: In a population showing exponential growth the individuals are not limited by food or disease. However, in most real populations both food and disease become important as conditions become crowded. [ There is an upper limit to the number of individuals the environment can support. Ecologists refer to this as the "carrying capacity" of the environment. Populations in this kind of environment show what is known as logistic growth.
Click the following button to run an applet you can use to experiment with logistic growth. If you are accessing this lesson over a slower network connection it may take several seconds for the applet to appear.
You must have Java installed and enabled to run this.
This applet is similar to the one you used with exponential growth. We assume you have have already worked with the Exponential Growth applet and are familiar with its controls and their functions. The only new field present is the carrying capacity field which is initialized at 1000.
While in the Habitat view, step the population for 25 generations. The population becomes quite crowded, but it levels off near 1000 individuals. Switch to the Graph view and you will see the classic "S" shaped curve that is characteristic of logistic growth. While the population is small it shows exponential growth. However, as the population approaches the carrying capacity the growth slows down and the curve levels off. ] (More)

Weegy: A .has a disproportionately large impact on an ecosystem due to its role in the survival of many other species.
A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance.[1] Such species [ play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community.
The role that a keystone species plays in its ecosystem is analogous to the role of a keystone in an arch. While the keystone is under the least pressure of any of the stones in an arch, the arch still collapses without it. Similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measures of biomass or productivity. It has become a very popular concept in conservation ] User: When a single species evolves into two species, the new species must (Points : 5)
be reproductively isolated.
evolve different diets.
be exposed to the same selective pressures.
live on a different continent. Weegy: B. evolve different diets User: On Earth today, mountains such as the Himalayas are rising because of (Points : 5)
extensive erosion caused by increases in rainfall in those regions.
human mining operations that are excavating large amounts of coal.
low pressure air systems focused above the mountains.
collisions between tectonic plates. Weegy: Mountains such as the Himalayas are rising due to collisions between tectonic plates. User: Darwin's concept of fitness is based on two separate abilities. These are the ability to (Points : 5)
survive and reproduce.
find a mate and have offspring.
defend against enemies and find food.
produce and defend a family. Weegy: Produce and defend a family.
User: In logistic growth, how does ... (More)